Patents Assigned to Cadence Design Systems
  • Patent number: 7412681
    Abstract: A computer implemented method is provided for use in evaluating a hierarchical representation of a circuit design encoded in a computer readable medium comprising: traversing a circuit path within a higher level circuit that includes a reference potential connection, to identify a port of a call to a first lower level circuit that is DC path connected to the reference potential; identifying a first DC port group that includes each port of the call to the first lower level circuit that is DC path connected to the identified port of the call to the first lower level circuit; automatically marking as DC path connected to the reference potential, each port of the call to the first lower level circuit that is a member of the first DC port group; and traversing a circuit path within the first lower level circuit to identify a circuit path within the first lower level circuit that is DC path connected to a marked port of the first lower level circuit.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: August 12, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Xiaodong Zhang, Jun Kong, Bruce W. McGaughy
  • Patent number: 7409656
    Abstract: Disclosed is an improved method and system for implementing parallel processing of computing operations by effectively handling dependencies between different sequences of computing operations. In some approaches, some or all operations corresponding to dependencies between different sequences of operations are duplicated among the different sequences. This approach may be used to implement parallel processing of EDA tools.
    Type: Grant
    Filed: September 12, 2005
    Date of Patent: August 5, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventor: Roland Ruehl
  • Patent number: 7409328
    Abstract: A system for communicating simulation solutions between circuit components in a hierarchical data structure includes a simulator module having one or more computer programs for representing the circuit as a hierarchically arranged set of branches, which includes a root branch and a plurality of other branches logically organized in a graph. The hierarchically arranged set of branches includes a first branch that contains one or more driver leaf circuits and a second branch that also contains one or more receiver leaf circuits, where the first branch and second branch are interconnected in the graph through a third branch at a higher hierarchical level in the graph than the first and second branches.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: August 5, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Bruce W. McGaughy, Jun Kong, Peter Frey, Jaideep Muhkerjee
  • Publication number: 20080184181
    Abstract: For increasing user control and insight into preparing a mixed-signal semiconductor design specification for simulation, there are provided methods responsive to commands that provide control over resolution of disciplines and partitioning of the design into analog and digital portions. In some aspects, the methods provide block-based assignment of disciplines, as well as design partitioning. In other aspects, the methods provide for resolving a discipline to apply in a block from among multiple possible disciplines. In some aspects, error flagging may be available for detecting disciplines different from what provided for assignment in a block. Assignments may be indicated based on instance, cell, terminal, or library names and may be specified with wild cards. In still other aspects, the methods may be embodied by instructions on computer readable media, and in systems comprising general and special purpose computer hardware that may communicate with various storage facilities and over various networks.
    Type: Application
    Filed: January 29, 2007
    Publication date: July 31, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Chandrashekar L. Chetput, Abhijeet Kolpekwar, Srinivasan Iyengar
  • Publication number: 20080184184
    Abstract: Method and system for conducting design explorations of an integrated circuit are disclosed. In one embodiment, the method includes obtaining a design description of the integrated circuit that includes a virtual design block, creating a representative netlist for representing the virtual design block, where the representative netlist includes one or more soft design models, and each soft design model comprises one or more template cells for modeling a portion of the integrated circuit. The method further includes defining physical attributes for the one or more soft design models in accordance with area requirements of the virtual design block, where the one or more soft design models are described with flexible shape and pin locations, performing design explorations of the integrated circuit using the one or more soft design models and their corresponding template cells, and generating a representative implementation of the integrated circuit using results of the design explorations.
    Type: Application
    Filed: January 30, 2007
    Publication date: July 31, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Thaddeus Clay McCracken, Jong-Chang Lee, Ping-Chih Wu, Cecile Nghiem, Kit Lam Cheong, Patrick John Eichenseer
  • Patent number: 7406405
    Abstract: A design verifier includes a bounded model checker, an abstractor and an unbounded model checker. The bounded model checker verifies a property to a depth K and either finds a counterexample, or generates a proof in the form of a directed acyclic graph. If no counterexample is found, the abstractor generates an abstracted design description using a proof generated by the bounded model checker. The unbounded model checker verifies the property of the abstracted design description. If a counterexample is found, the bounded model checker increases K and verifies the property to the new larger depth. If no counterexample is found, the design is verified.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: July 29, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Kenneth L. McMillan, Nina Amla
  • Patent number: 7398503
    Abstract: A method for pre-tabulating sub-networks that (1) generates a sub-network that performs a function, (2) generates a parameter based on this function, and (3) stores the sub-network based on the parameter. In some embodiments, the generated sub-network has several circuit elements, performs two or more functions, or is stored in an encoded manner. A method for producing a circuit description of a design that (1) selects a candidate sub-network from the design, (2) identifies an output function performed by the sub-network, (3) based on the identified output function, identifies a replacement sub-network from a storage structure, and (4) replaces the candidate sub-network with the replacement sub-network in certain conditions. In some embodiments, this method is performed to map a design to a particular technology library. Some embodiments provide a data storage structure that stores sub-networks based on parameters derived from the output functions of the sub-networks.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: July 8, 2008
    Assignee: Cadence Design Systems, Inc
    Inventors: Steven Teig, Asmus Hetzel
  • Patent number: 7397320
    Abstract: A non-uniform transmission line, including at least a first section with length L1, uniform width W1 and thickness h1, and a second section with length L2, uniform width W2 and thickness h2, joined together to form a composite structure and arranged in any of at least three distinct configurations. The composite structure (first section plus second section) may be periodic or non-periodic. Length and/or width and/or thickness of each of the two sections may be varied to provide desired values for characteristic impedance, cutoff frequency and/or time delay for signal propagation.
    Type: Grant
    Filed: May 16, 2001
    Date of Patent: July 8, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventor: Syed Asadulla Bokhari
  • Patent number: 7398498
    Abstract: Some embodiments of the invention provide a method that pre-computes routes for groups of related net configurations. These routes are used by a router that uses a set of partitioning lines to partition a region of a design layout into a plurality of sub-regions. The method identifies groups of related sub-region configurations. For each group, the method stores a base set of routes. For each configuration in each group, the method also stores an indicia that specifies how to obtain a related set of routes for the particular configuration from the base set of routes stored for the configuration's group.
    Type: Grant
    Filed: January 4, 2002
    Date of Patent: July 8, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Steven Teig, Joseph L. Ganley
  • Publication number: 20080163134
    Abstract: Disclosed is a method, system, and computer program product for implementing model-based layout, placement, and routing. Models are used to guide the placement and routing of polygons on the IC layout. In effect, the parameters that are used for placement and routing are guided by the model data so that the layout can be formed with a high degree of manufacturability from the outset.
    Type: Application
    Filed: December 29, 2006
    Publication date: July 3, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Eric Nequist, Richard Brashears
  • Patent number: 7393755
    Abstract: A method and system are described to reduce process variation as a result of the electrochemical deposition (ECD), also referred to as electrochemical plating (ECP), and chemical mechanical polishing (CMP) processing of films in integrated circuit manufacturing processes. The described methods use process variation and electrical impact to direct the insertion of dummy fill into an integrated circuit.
    Type: Grant
    Filed: June 7, 2002
    Date of Patent: July 1, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Taber H. Smith, Vikas Mehrotra, David White
  • Patent number: 7395516
    Abstract: Some embodiments of the invention provide a process for designing and manufacturing an integrated circuit (“IC”). The process selects a wiring configuration and an illumination configuration. The process uses the selected wiring configuration to design an IC layout. The process then uses the selected illumination configuration to manufacture the IC based on the designed IC layout. Some embodiments concurrently select an optimal pair of wiring and illumination configurations. Other embodiments select an illumination configuration based on the selected wiring configuration. Yet other embodiments select a wiring configuration based on the selected illumination configuration. In some embodiments, selecting the illumination configuration entails selecting at least one stepper lens for the IC layout, where the stepper lens illuminates at least one mask for at least one particular layer of the IC layout. In some embodiments, this selection entails selecting a stepper lens for each particular layer of the IC layout.
    Type: Grant
    Filed: August 28, 2005
    Date of Patent: July 1, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Akira Fujimura, Louis K. Scheffer
  • Patent number: 7392170
    Abstract: A system for dynamically compressing circuit components during simulating of a circuit having a hierarchical data structure includes a simulator module having one or more computer programs for 1) selecting a group of leaf circuits from the first and second branches for simulation, 2) if two or more leaf circuits of the circuit having a substantially same isomorphic behavior, representing the two or more leaf circuits as a merged leaf circuit, 3) creating a first port connectivity interface dynamically for the group of leaf circuits in response to the merged leaf circuit, where the first port connectivity interface communicates changes in signal conditions among the group of leaf circuits, and 4) simulating the group of leaf circuits in accordance with the first port connectivity interface.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: June 24, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Bruce W. McGaughy, Jun Kong
  • Patent number: 7392255
    Abstract: A federated system and methods and mechanisms of implementing and using such a system is disclosed. In some embodiments, one or more mappings are created between a taxonomy view at a node and one or more taxonomies of one or more data sources. The one or more data sources can then be accessed via the taxonomy view. In other embodiments, one or more mappings are created between content from different data sources and content from those data sources are merged using the one or more mappings.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: June 24, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Steven Sholtis, Rick Glenn Tachibana, Thomas Auga, Kenneth Jerome Henderson, Venkata S. J. R. Bhamidipati
  • Publication number: 20080147372
    Abstract: An automated method and system for managing simulation results of a virtual circuit. Data related to the virtual circuit is accessed. The virtual circuit is subject to a simulation. An initiation of each of one or more transactions occurred during the simulation is identified, and data related to the one or more transactions during the simulation is collected. Upon receipt of a user request, the collected data related to the one or more transactions is output, displayed, stored or made available for review or further processing.
    Type: Application
    Filed: December 14, 2006
    Publication date: June 19, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventor: William R. PAULSEN
  • Publication number: 20080148216
    Abstract: A method and apparatus for mask optimization is provided. Mask design and production is optimized by providing proper weighting parameters for critical features. The parameters may include information such as parametric information, functional information, and hot spots determination.
    Type: Application
    Filed: December 18, 2006
    Publication date: June 19, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Kevin Chan, Emmanuel Drege, Nickhil Jakatdar, Svetlana Litvintseva, Mark A. Miller, Francis Raquel
  • Publication number: 20080148194
    Abstract: A method and apparatus for process optimization is provided. Process optimization improves parametric and functional yield post mask manufacturing.
    Type: Application
    Filed: December 18, 2006
    Publication date: June 19, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Kevin Chan, Emmanuel Drege, Nickhil Jakatdar, Svetlana Litvintseva, Mark A. Miller, Francis Raquel
  • Publication number: 20080147374
    Abstract: A method and apparatus for modeling and cross correlation of design predicted criticalities include a feedback loop where information from the manufacturing process is provided to cross correlation engine for optimization of semiconductor manufacturing. The information may include parametric information, functional information, and hot spots determination. The sharing of information allows for design intent to be reflected in manufacturing metrology space; thus, allowing for more intelligent metrology and reduces cycle time.
    Type: Application
    Filed: December 18, 2006
    Publication date: June 19, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Kevin Chan, Emmanuel Drege, Nickhil Jakatdar, Svetlana Litvintseva, Mark A. Miller, Francis Raquel
  • Publication number: 20080148195
    Abstract: A method and apparatus for inspection optimization is provided. Inspection optimization improves the parametric and functional yield using optimized inspection lists for in-line semiconductor manufacturing metrology and inspection equipment.
    Type: Application
    Filed: December 18, 2006
    Publication date: June 19, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Kevin Chan, Emmanuel Drege, Nickhil Jakatdar, Svetlana Litvintseva, Mark A. Miller, Francis Raquel
  • Publication number: 20080136532
    Abstract: An adaptive phase-locked loop (PLL) circuit produces an output signal having a frequency in reference to the frequency of a reference signal. The PLL circuit includes an oscillator configured to generate the output signal according to a frequency control signal, and a processing circuit configured to generate a feedback signal deriving from the output signal. An adjustable shift circuit is provided to time-shift the feedback signal. The PLL further includes a phase comparison circuit configured to generate a phase error signal indicating a phase error between the time-shifted feedback signal and the reference signal, and a control circuit configured to generate the frequency control signal based on the phase error signal. The adjustable shift circuit adjusts a time-shift amount to time-shift the feedback signal according to the phase error signal.
    Type: Application
    Filed: December 7, 2006
    Publication date: June 12, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Michael M. HUFFORD, Eric Naviasky, Tony Caviglia